Radio frequency power supply matcher

Abstract

The utility model discloses a radio frequency power supply matcher, which comprises a detection module, an impedance calculation unit, a switching control module and a capacitor module, and is characterized in that the capacitor module comprises a plurality of capacitor banks containing four capacitors with different ratios, and the capacitors at the same positions in adjacent capacitor banks have a ratio relation of 1: 10; the impedance calculation unit converts an output signal of the detection module into a matching impedance signal, and the switching device connected in series with the capacitor is controlled through the switching control module, so that high-precision matching and rapid response of impedance between the radio frequency power supply and the load are realized, and the impedance matching range and precision are greatly expanded; and stable operation of the radio frequency power supply is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a radio frequency power supply matcher. Background Art

[0002] RF power supplies are widely used in many fields, including semiconductor process equipment, LEDs and solar photovoltaics, plasma generation in scientific experiments, RF induction heating, medical cosmetology, and atmospheric pressure plasma disinfection and cleaning. However, due to the uncertainty of the RF power supply load, a matcher must be used to achieve impedance matching between the load and the RF power supply to ensure the normal operation of the system.

[0003] Traditional matchers typically use mechanical adjustment, relying on vacuum capacitors or adjustable capacitors, and changing the capacitance value by driving the capacitor plates with a step voltage. This method is not only susceptible to leakage and oxidation, but also has limited adjustment accuracy, with deviations often exceeding 5%. At the same time, the response speed of mechanical adjustment is slow. However, different application scenarios have strict requirements on matching time. For example, in many high-efficiency production environments, the matching process must be completed within 500 milliseconds.

[0004] Therefore, there is an urgent need for a new type of RF power supply matcher that can solve the problem of slow mechanical adjustment response speed. Utility Model Content

[0005] The purpose of the present invention is to overcome the above technical deficiencies, propose a radio frequency power supply matcher, and solve the problems raised in the background technology.

[0006] To achieve the above technical objectives, the technical solution of the present invention provides a radio frequency power supply matcher, comprising: a detection module, an impedance calculation unit, a switching control module and a capacitor module, wherein the detection module is used to obtain a reflected signal fed back by a load; the impedance calculation unit converts the reflected signal into a matching impedance signal for output; a switching control module and a capacitor module, wherein the switching control module controls the switching of the capacitor module according to the matching impedance signal; the capacitor module comprises a plurality of capacitor groups connected in parallel, wherein the capacitor group comprises four capacitors connected in series with the switch and then in parallel, and the capacity ratio of the four capacitors is 1:1:2:5; the capacity ratio of the capacitors at the same position in two adjacent capacitor groups is 1:10.

[0007] Furthermore, the switching control module uses the matching impedance signal as a target value to control the switches in the capacitor modules respectively, so that the capacitors connected in series therewith are switched in a step-by-step manner.

[0008] Furthermore, the switching control module simultaneously controls the opening and closing of the switch in the capacitor module, so that the impedance of the capacitor module immediately adapts to the matching impedance signal.

[0009] Furthermore, the detection module includes a directional coupler and an amplifier and a filter connected thereto, and the impedance calculation unit includes an analog-to-digital converter and a digital signal processing module connected thereto. The digital signal processing module calculates the impedance to be compensated based on the collected signal and outputs it to the switching control module.

[0010] Furthermore, the capacitors in the capacitor bank are solid-state capacitors, and the switches are solid-state relays, MOSFET switches or IGBTs.

[0011] Compared with the prior art, the beneficial effects of the present invention include:

[0012] 1. The capacitor module of the present invention includes four capacitor groups with different capacitance ratios, and the capacitors at the same position in adjacent capacitor groups have a ratio of 1:10. By switching the capacitors through a switcher connected in series with the capacitors, high-precision impedance matching and fast response between the RF power supply and the load are achieved, thereby greatly expanding the range and accuracy of impedance matching and ensuring the stable operation of the RF power supply.

[0013] 2. The switching control module of the present invention is provided with two switching modes. It can gradually approach the matching impedance by gradually controlling the switching of the switchers in the capacitor bank, or quickly achieve impedance matching by simultaneously controlling the switching of multiple switchers. This design not only meets the needs of different application scenarios, but also significantly improves the response speed of the matching device. Especially in scenarios where the load impedance changes frequently, the present invention can quickly adjust the impedance of the capacitor module to keep the impedance between the RF power supply and the load matched, thereby effectively reducing the power loss and signal distortion caused by impedance mismatch. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of a radio frequency power supply matcher provided by the present utility model;

[0015] Figure 2 This is a schematic diagram of a detection module and impedance calculation unit of a radio frequency power supply matching device provided by the utility model;

[0016] Figure 3 This is a schematic diagram of a capacitor module of a radio frequency power supply matcher provided by the utility model. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] Reference Figure 1 、 Figure 2 The utility model provides a radio frequency power supply matcher, including a detection module, an impedance calculation unit, a switching control module and a capacitor module.

[0019] The specific implementation method of the detection module is to obtain the reflected signal of the load feedback through a directional coupler; the directional coupler leads out the reflected signal and transmits it to the amplifier connected to it for signal amplification, and then passes it through the filter for filtering to ensure the accuracy and stability of the signal.

[0020] The impedance calculation unit includes an analog-to-digital converter and a digital signal processing module. The analog-to-digital converter converts the amplified and filtered analog signal into a digital signal. The digital signal processing module then performs algorithmic processing on these digital signals, calculates the impedance to be compensated according to a preset algorithm, and outputs this matching impedance signal.

[0021] Reference Figure 3 The capacitor module is designed with several parallel capacitor groups C1-C N Each capacitor bank contains four capacitors C N01 -C N04 , these four capacitors are connected through the switch KM N01 -KM N04 The four capacitors are connected in series and then in parallel; the ratio of these four capacitors is 1:1:2:5 to provide a diverse capacitor combination and achieve more precise impedance matching. At the same time, to expand the impedance matching range and improve matching accuracy, the ratio of the capacitors at the same position in two adjacent capacitor groups is 1:10.

[0022] The following example uses three capacitor banks:

[0023] The four capacitors C in C1 101 -C 104 , whose capacity is 1pF, 1pF, 2pF, 5pF, using 4 switchers KM 101 -KM 104 Connect each capacitor in series and then in parallel, through KM 101 -KM 104 The switching can achieve an adjustable capacitance range of 1pF to 9pF.

[0024] The four capacitors C in C2 201 -C 204 , whose capacity is 10pF, 10pF, 20pF, 50pF, using 4 switchers KM 201 -KM 204 Connect each capacitor in series and then in parallel, through KM 201 -KM 204 The switching can achieve an adjustable capacitance range of 10pF to 90pF.

[0025] The four capacitors C in C3 301 -C 304 , whose capacity is 100pF, 100pF, 200pF, 500pF, using 4 switchers KM 301 -KM 304 Connect each capacitor in series and then in parallel, through KM 301 -KM 304 The switching can achieve an adjustable capacitance range of 100pF to 900pF.

[0026] By connecting the units C1-C3 in parallel, the range of 0-999pF can be adjusted with a step of 1pF, which can achieve an adjustment accuracy of 0.1% (i.e. 1‰).

[0027] The withstand voltage of the capacitors and switches in the capacitor bank can be selected according to the circuit working type level. For example, if the circuit voltage is 100V, a withstand voltage of 200V can be selected. Due to the solid-state characteristics, its parameters remain basically unchanged at temperatures between -20 and +60 degrees Celsius, and all finished products are externally potted to eliminate the influence of humidity. The use of solid-state switching can control the matching time within 100ms, greatly improving the response rate. According to the corresponding speed requirements of different application scenarios, the switch can be selected from solid-state relays, MOSFET switches or IGBTs, and the corresponding drive circuit is configured in the switching control module.

[0028] In practical applications, when the impedance between the RF power supply and the load does not match, the detection module will obtain the reflected signal fed back by the load in real time and calculate the impedance required for compensation through the impedance calculation unit. Then, the switching control module controls the switching operation of the switch in the capacitor module based on this matching impedance signal, adjusting the impedance of the capacitor module to match the impedance between the RF power supply and the load. In this way, the reflected power can be effectively reduced and the transmission efficiency and stability of the RF power supply can be improved.

[0029] In actual application, the switching control module has two switching modes:

[0030] 1. The switching control module uses the matching impedance signal as the target value and gradually controls the switching of the switchers in each capacitor bank to gradually make the impedance of the capacitor module approach the matching impedance signal. This is suitable for scenarios with high matching accuracy requirements. This switching mode simulates the existing mechanical adjustment and has similar electrical characteristics and faster response speed.

[0031] 2. The switching control module takes the matching impedance signal as the target value and controls C1-C nThe switch in the capacitor module is turned on and off, so that the impedance of the capacitor module immediately adapts to the matching impedance signal, thereby achieving the purpose of impedance matching. This switching mode has a faster response speed and is suitable for scenarios where the load impedance changes frequently.

[0032] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A radio frequency power supply matching device, comprising: A detection module, the detection module is used to obtain a reflected signal of load feedback; an impedance calculation unit, wherein the impedance calculation unit converts the reflected signal into a matching impedance signal for output; A switching control module and a capacitor module, wherein the switching control module controls the switching of the capacitor module according to the matching impedance signal; The characteristic is that the capacitor module includes a plurality of capacitor groups connected in parallel, and the capacitor group includes four capacitors connected in series with the switch and then in parallel, and the capacity ratio of the four capacitors is 1:1:2:5; the capacity ratio of the capacitors at the same position in two adjacent capacitor groups is 1:

10.

2. The radio frequency power supply matching device according to claim 1, characterized in that: The switching control module uses the matching impedance signal as a target value to control the switches in the capacitor modules respectively, so that the capacitors connected in series therewith are switched in a step-by-step manner.

3. The RF power supply matching device according to claim 1, wherein: The switching control module simultaneously controls the switching of the switch in the capacitor module, so that the impedance of the capacitor module immediately adapts to the matching impedance signal.

4. A radio frequency power supply matching device according to claim 2 or 3, characterized in that: The detection module includes a directional coupler and an amplifier and a filter connected thereto. The impedance calculation unit includes an analog-to-digital converter and a digital signal processing module connected thereto. The digital signal processing module calculates the impedance to be compensated based on the collected signal and outputs it to the switching control module.

5. The radio frequency power supply matching device according to claim 4, characterized in that: The capacitors in the capacitor bank are solid-state capacitors, and the switch is a solid-state relay, a MOSFET switch or an IGBT.

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